I believe that SSG was available for e46s for a short time (2004-2005), but it wasn't very popular. I saw someone at a recent Autox event that had SSG in his e46 sedan and he had these same paddles.

These SSG Paddles are retrofitted on the sport-steering wheel of my 01 330Ci. I've had them on for a few years now. I only use them maybe 10-15% of the time though. I'm always in Manual mode, but I generally use the shifter instead. Great for the Track and canyon runs though! And yea, that Z8 Start Button actually works.